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18 Cards in this Set
- Front
- Back
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What is the function of the Smooth and Rough endoplasmic reticulum?
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Smooth- Synthesises and processes lipids
Rough- Folds and processes proteins that have been made at the ribosomes. |
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What is the function of the golgi apparatus?
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Processes and packages new lipids and proteins and transports them around the cell using vesicles.
It also makes lysosomes. |
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What is the equation to calcualte magnification?
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Magnification= Length of image/ Length of specimen.
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Name 1 advantage of a TEM and 1 advantage of an SEM.
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TEM- Higher Resolution than an SEM
SEM- Can be used on thick specimens and produces 3D images. |
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Name the three stages of cell fractionation and explain what happens at each step.
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1. Homogenisation- Cells are grinded to break their cell membrane and release the organelles.
2. Filteration- The solution is filtered to separate the organelles from large debris. 3. Ultracentrifugation- The solution is spun in a centrifuge. This causes a pellet to be made of the heaviest organelle. You can spin the supernatant again until you separate the organelle required. |
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Why is the plasma membrane known as Fluid- Mosaic?
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It is known as Fluid because the phopholipid bi layer is flexible and is constantly moving. The protein molecules scattered through the layer is what makes it Mosaic.
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What is the difference between an unstaurated fattty acis and a saturated fatty acid?
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Unstaurated fatty acid has a Carbon double bond, this causes the chain to kink.
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What bond forms in a triglyceride?
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Ester Bond.
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Describe the emulsion test for lipids.
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1. Shake the substance with ethanol then pour the solution into water.
2. Any lipid will show up as a milky/ cloudy emulsion. |
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The net movement of particle from an area of high concentration to an area of low concentration
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Diffusion
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The net movement of water particles from an area of high water potenial to an area if low water potential across a semi permeable membrane.
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Osmosis
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What is the water potential of pure water?
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Zero
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Explain isotonic, hypotonic and hypertonic.
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Isotonic- where two solutions have the same water potential.
Hypotonic- Outside a cell has higher WP than inside. Hypertonic- Cell has high WP than outside the cell |
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Is facilitated diffusion an active or passive process?
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Passive
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What is co-transport?
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Where the concentration gradient of one substance is used to move another against its concentration gradient.
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Decribe the stucture of a prokaryotic cell.
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Cell membrane, Cell wall, ribosomes, circular DNA (NO NUCLEUS), Plasmids, Flagellum, Secreted slime layer.
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How does the cholera toxin cause diorrhoea?
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The toxin causes chloride ion channels in the gut wall to open. This means chloride ions move into the lumen of the small intestine. This lower the water potential and so water moves, by osmosis, from the blood and into the lumen. The massive increase in water in the lumen causes severe diarrhoea.
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Explain how an ORS works.
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The ORS replaces the lost nutrients from diarrhoea. An ORS conatains sugars (glucose) and salts (sodium and chloride ions) dissolved in water. Sodium ions increase glucose absorption because of co transport.
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